In the official IPA chart, alveolo-palatals would appear between the retroflex and palatal consonants but for "lack of space".
[2] These descriptions are essentially equivalent, since the contact includes both the blade and body (but not the tip) of the tongue (see schematic at right).
According to Daniel Recasens, alveolo-palatal consonants are realized through the formation of a simultaneous closure or constriction at the alveolar and palatal zones with a primary articulator which encompasses the blade and the tongue dorsum.
Although a number of spoken Chinese varieties, such as standard Mandarin, also contrast EMC alveolo-palatal nasal with velar nasal of class III (palatalizing medial), most don't contrast them in a way that alveolo-palatal differs from palatal.
ȶ, on the other hand, has retained its accurate usage representing phonemes in certain spoken Chinese in Hengyang and has never been applied on Hakka or on certain Mandarin in or near Shandong.